scsi: hisi_sas: Fix NULL pointer dereference

There is a NULL pointer dereference in case *slot* happens to be NULL at line 1878:

struct hisi_sas_cq *cq =

	&hisi_hba->cq[slot->dlvry_queue];

Notice that *slot* is being NULL checked at line 1881: if (slot), which implies it may be NULL.

Fix this by placing the declaration and definition of variable cq, which contains the pointer dereference slot->dlvry_queue, after *slot* has been properly NULL checked.

Addresses-Coverity-ID: 1474515 ("Dereference before null check")

Fixes 584f53fe5f52 ("scsi: hisi_sas: Fix the race between IO completion and timeout for SMP/internal IO")

Signed-off-by Gustavo A. R. Silva <[email protected]>

---
 drivers/scsi/hisi_sas/hisi_sas_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

drivers/scsi/hisi_sas/hisi_sas_main.c +2 -2

index 2e5eaf1..e3f7c7b 100644
@@ -1875,10 +1875,10 @@ hisi_sas_internal_task_abort(struct hisi_hba *hisi_hba,
 	if ((task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
 		if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
 			struct hisi_sas_slot *slot = task->lldd_task;
-			struct hisi_sas_cq *cq =
-				&hisi_hba->cq[slot->dlvry_queue];
 
 			if (slot) {
+				struct hisi_sas_cq *cq =
+					&hisi_hba->cq[slot->dlvry_queue];
 				/*
 				 * flush tasklet to avoid free'ing task
 				 * before using task in IO completion